/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc=new Scanner(System.in);
		int t=sc.nextInt();
		while(t-->0)
		{
			int n=sc.nextInt();
			long x[]=new long[n];
			long y[]=new long[n];
 
			for(int i=0;i<n;i++)
			{
 
				x[i]=sc.nextLong();
				y[i]=sc.nextLong();
			}
 
			Arrays.sort(x);
			Arrays.sort(y);
 
			long minarea;
			if(n<=0)
			minarea=0;
			else if(n==1)
			minarea=1;
			else
			{
			 minarea=( (x[n-1]-x[0]+1)*(y[n-1]-y[0]+1));
 
			// removing left x
			long area1=( (x[n-1]-x[1]+1)*(y[n-1]-y[0]+1));
			minarea=Math.min(minarea,area1);
 
			// removing right x
			long area2=( (x[n-2]-x[0]+1)*(y[n-1]-y[0]+1));
			minarea=Math.min(minarea,area2);
 
				// removing left y
			long area3=( (x[n-1]-x[0]+1)*(y[n-1]-y[1]+1));
			minarea=Math.min(minarea,area3);
 
			// removing right y
			long area4=( (x[n-1]-x[0]+1)*(y[n-2]-y[0]+1));
			minarea=Math.min(minarea,area4);
 
			// removing left x , down y
			long area5=( (x[n-1]-x[1]+1)*(y[n-1]-y[1]+1));
			minarea=Math.min(minarea,area5);
 
 
				// removing right x, top y
			long area6=( (x[n-2]-x[0]+1)*(y[n-2]-y[0]+1));
			minarea=Math.min(minarea,area6);
			}
 
			System.out.println(minarea);
 
 
 
 
 
 
		}
	}
}

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7
3
1 1
1 2
2 1
5
1 1
2 6
6 4
3 3
8 2
4
1 1
1 1000000000
1000000000 1
1000000000 1000000000
1
1 1
5
1 2
4 2
4 3
3 1
3 2
3
1 1
2 5
2 2
4
4 3
3 1
4 4
1 2